To learn more about the human heart’s response to prolonged exposure to space’s microgravity, you just have to look at the fruit fly, scientist Karen Ocorr says.

To advance that research, she will send dozens of the pesky little bugs to the International Space Station from Florida on Thursday, if all goes as planned.

SpaceX plans to launch one of its Falcon 9 rockets into space from historic Launch Complex 39A. The expected 5:55 p.m. launch — the 11th of as many as 20 resupply missions SpaceX plans to send under its contract with NASA — will carry nearly 6,000 pounds of cargo to the International Space Station.

The original contract had been for 12 missions but that number has since grown.

SpaceX, which has been pursuing reusability of its rockets, also will be relaunching one of its Dragon cargo spacecraft, which returned from the space station and was recovered in 2014.

The liftoff will mark the 100th launch from Launch Complex 39A, which SpaceX now leases.

The 100th launch from Launch Pad 39A at Kennedy Space Center is set for Thursday, June 1, 2017. Take a look at some photos from 39A through the years.

That pad hosted the Apollo 11 mission, which sent Neil Armstrong and Buzz Aldrin to the moon, in 1969.

Included in Thursday’s cargo mission are several scientific experiments, including one that will test a new solar-panel concept that could someday power electric thrusters on NASA’s future space vehicles.

Another experiment will look at whether bone loss in space can be reversed.

But for Ocorr, it’s all about the fruit flies.

“We use them as a model to understand human heart function,” said Ocorr, a Sanford Burnham Prebys scientist based in California.

Ocorr, who is in Florida for the launch, said fruit flies’ hearts function more like humans’ than even the always popular lab rats and mice.

She has yet to witness a rocket launch in person. In 2014, she was in Florida for a previous flight that was part of fruit-fly research. But multiple scrubs scrapped that plan, and she had to return to California before the mission actually took off.

So Thursday’s planned launch has extra meaning for her.

Still, her primary concern is the tiny cargo.

“The rumbling vibration, the sound, it should be an altogether amazing experience and I’m looking forward to that,” Ocorr said.“But also to knowing that my flies are headed in the right direction.”

Note: An earlier version of this story incorrectly characterized SpaceX’s contract with NASA.

Long past its peak during the Cold War era, the UFO believer community lives on in meeting rooms across the U.S. and along the Space Coast. And it's recently started to pick up unlikely allies: Scientists.

Long past its peak during the Cold War era, the UFO believer community lives on in meeting rooms across the U.S. and along the Space Coast. And it's recently started to pick up unlikely allies: Scientists.

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Long past its peak during the Cold War era, the UFO believer community lives on in meeting rooms across the U.S. and along the Space Coast. And it's recently started to pick up unlikely allies: Scientists.

Long past its peak during the Cold War era, the UFO believer community lives on in meeting rooms across the U.S. and along the Space Coast. And it's recently started to pick up unlikely allies: Scientists.

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NASA Administrator Jim Bridenstine revealed the agency's fiscal year 2020 budget proposal at an event at Kennedy Space Center Monday. It will focus largely on NASA's plans to return to the moon.

NASA Administrator Jim Bridenstine revealed the agency's fiscal year 2020 budget proposal at an event at Kennedy Space Center Monday. It will focus largely on NASA's plans to return to the moon.

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NASA tested a developmental RS-25 engine with the flight controller (or brain) for the Space Launch System at the A-1 Test Stand at the Stennis Space Center on Feb. 28. It was the last of nine tests since August 2018 in a series to test the flight controllers. The engine burn at 113 percent capacity lasted for 510 seconds.

NASA tested a developmental RS-25 engine with the flight controller (or brain) for the Space Launch System at the A-1 Test Stand at the Stennis Space Center on Feb. 28. It was the last of nine tests since August 2018 in a series to test the flight controllers. The engine burn at 113 percent capacity lasted for 510 seconds.

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The SpaceX Demo-1 launch of a Falcon 9 with the Crew Dragon capsule launched from Kennedy Space Center in the early morning hours of Saturday, March 2, 2019.

The SpaceX Demo-1 launch of a Falcon 9 with the Crew Dragon capsule launched from Kennedy Space Center in the early morning hours of Saturday, March 2, 2019.

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Astronauts will use the Crew Access Arm at Kennedy Space Center's Launch Complex 39A when boarding the SpaceX Crew Dragon when it launches atop Falcon 9 rockets to the International Space Station.

Astronauts will use the Crew Access Arm at Kennedy Space Center's Launch Complex 39A when boarding the SpaceX Crew Dragon when it launches atop Falcon 9 rockets to the International Space Station.